Apparatus for supplying heated oil



K. A. JUTHE ET AL 1,329,186

APPARATUS FOR SUPPLYING HEATED OIL Filed aan. s, 192e 5 sneet-sneei 1 Oct. 27, V1931. K. AA JuTHE ET AL APPARATUS FOR SUPPLYING HEATE OIL Filed Jan. 3, 1928 Jew/the,

Oct. 27, 1931. K. A. JUTHE ET AL 1,829,186

APPARATUS FOR SUPPLYING HEATED OIL Filed Jan. 5, 1928 5 Sheets-Shet 3 Ik@ J6 54 w-W film ZZWQMZ v A V Oct. 27, 1931. k. A. JUTHE ET AL 1,829,186

APPARATUS FOR SUPPLYING HEATED OIL Filed Jan. 3, 1928 ,'5 Sheets-Sheet` 4 Oct. 27, 1931. K. A` JUTHE ET AL. 1,829,186

APPARATUS FOR SUPPLYING HEATED OIL Filed Jan. 5, 1928 5 Sheets-Sheet 5- Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE KRISTIAN A. JUTHE, OF NEWTON,k AND ALBERT J'. HANSON, 0F ARLINGTON, MASSACHU- SETTS, ASSIGNORS TO AMERICAN ELECTRIC FUBNACE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS APPARATUS FOR SUPPLYING HEATED OIL Application filed January 3, 1928. Serial No. 244,288.

This invention relates to a method of and means for heat-treating steel castings and the like by providing a bath of heated liquid in which the castings may be immersed, and heating the liquid for the bath at a point outside the bath. An object of the invention is to provide means for automatically controlling the temperature of the batli by the circulation of heated oil therethrough, and to safeguard the apparatus against overheating. In carrying out the invention, means are provided for circulating liquid, such as oil, around a system which includes a tank for the treating bath and a furnace for reheating the oil drawn from the bath and reintroducing the heated oil into the bath. The temperature of the oi-l entering the bath is regulated automatically by means responsive to temperature conditions in the bath for controlling the operation of the furnace. Means for safeguarding the apparatus from overheating include a thermostatic device in the pipe line leaving the furnace for cutting oil the heat When the oil leaving the furnace exceeds a predetermined temperature, and apparatus for automatically cutting off the heat if the circulating pump stops.

Another object of the invention is to supply heated oil with or Without additional cool oil simultaneously to a plurality of baths of independent temperatures, the oil supply to each being automatically controlled to maintain the several temperatures of the different baths. Various other advantageous features of the invention will be apparent to one skilled in the art from the following description of the invention and from the drawings7 of Which,-

Figure 1 is an elevation of apparatus enibodying the invention, a portion being shown in section.v

Figure 2 is a` section on the line 2 2 of Figure 1.

Figure 3 is a plan view of the apparatus shown in Figure 1.

Figure 4 is a side elevation of the furnace, the walls being in section to show the ar rangement of parts inside.

Figure 5 is a fragmentary section on the line 5--5 of Figure 4.

Figures 6 and 7 illustrate modified forms y of furnaces for heating liquid.

Figure 8 is a diagram of wiring which may be used in connection with the apparatus shown in Figure 1.

Figures 9 and 10 show diagrammatically, arrangements of apparatus for regulating the temperature in a plurality of tanks by the supply of liquid thereto'. f

Referring to the drawings in detail, 10 represents a work-treating tank which is adapted to receive hot liquid such as oil. This tank is preferably lagged with heatinsulating material. and may be provided with a removable'cover 11. Among the uses of a tank of this kind in industry is its employment to hold hot oil into which steel castings and the like may be dipped in order to draw their temper to the desired extent after having been heated and quenched to "i" hardness. As indicated in Figure 1, a suitable basket or receptacle 12 may be provided to hold the Work which is inserted into the tank for treatment. The tank 10 may be divided into two compartments 13, 14 as by a partition 15 which extends upwardly from the bottom of the tank to a level near but below the top thereof. In the compartment 13 a perforated plate 16 may be secured in a horizontal position dividing the compartment i into upper and lower chambers. This plate 16 serves as a false flooring to take the weight of the basket 12 and to protect apparatus parts located in the lower chamber 17. In order to supply heated oil or other suitable liquid to the tank 10, av furnace 18 may be provided, this furnace containing one or more coils of pipe 19 and a plurality of heating units 20. Each coil 19 is connected to a delivery pipe 21 which enters the tank 10 and terminates at its delivery end in the chamber 17. As shown, the delivery end may consist of a series of horizontally disposed pipes 22 having perforations distributed thereover so that the heated oil enters the tank at a multiplicity of spaced points within the charnber 17. The oil introduced into the chamber 17 intermixes with the oil already there and this mixture is forced through the perforations of the plate 16 into the work-containing portion of the compartment 13 so that a constant upward flow is maintained through this compartment. iis heated oil is introduced into the chamber 17, an equal amount of oil overiiows into the Chamber 1d which acts as a sump and communicates at its lower end with a drain pipe 23 which entends to a pump 2% dri *en as by a suitable motor 25 through reduction gearing` 28. rEhe oil which is drawn from the sump 1i through the pipe 23 is sentthrough a pipe 27 to th furnace 18 where it is reheated as it fiows through the coil 19 and continues on through the supply pipe 21, thus returning to the tank 1G. il storage tanl: 28 may be provided having` a connection 28 through which oil may be drained from the compartment 13 when it is desired to empty this compartment. and a connection from the bottom of the storage tanl; to the pump 2% by which oil may be drawn from thi tank during the operation of the apparatus t replenish oil which may leali out or otherwise be lost.

rI'he furnace 18, as previously described, preferably contains one or more coils of pipe 19 (one beine4 shown) through which the oil flows. As shown in Figures and 5. the furnace 18 may conveniently comprise a cylindrical casing` lagged with heat-insulat ing material. the coil 19 being arranged therein closely adjacent to the side walls thereof. lWithin the coil 19 the heating units Q0 are arranged as desired. The heating units may comprise elongated slabs of heatresistant material having* notches in their edges to receive a ribbon 31 of resistance metal which may be wound thereon. A number of these heating' elements may be arranged to extend radially edgewise within the coil 19 as illustrated in Fir/.jure 5. This arrangement of parts minimizes mutual heatin;r between the turns of the ribbon 31 on the units and between the several units themselves so that a larger current may be passed through the units without endangering; the ribbons 3i. Modified forms of heating elements are illustrated in Figures 6 and i', the former showing' a series of tiles 32 harina; grooves to receive coils of resistance wire The tiles 32 are supported in such a :ay that the coils are held opposed to the pipe coil 19 so that the hot wires 33 will radiate directly against the pipes. ln the form of heater shown in Fieri 7. a cylinder 34 of heatresistant material is inserted within tl pipo coil 19. the outer diameter of this c heine` slightly less than the inner diameter of the coil 19. The cylinder may he provided with a series of peripheral grooves 35 in which are located resistance elements which may consist of suidible metal ribbon or wire bent in the Zigz..jr forni as shown. rEhe several resistance elements 38 may be connected up as desired in series parallel or otherwise according to the resistance of each element and the voltage supplied.

ln order to regulate the temperature of the coil in the chamber 13, means is provided for contr ring the furnace 18 so that the oil which delivered therefrom to the chamber 1? may be suitable tenu'ierature to maintain the pool of oil in the compartment 13 at the desired temperature. To this end.v a heatri pensive element 37 may be located at any desired point within the compartment 13. shown.. the eleincnt 3'". located within the chamber 1T and communicates with a tl'iermostatic device 38 by which the electric current supplied to the furnace 18 is automatically turned on and olf in accordance with the temperature conditions in the chamber 1T. The apparatus by which the current .f-fupnlied to the furnace 18 is controlled is shown diag-rammatically only as it is old and woll lnori'n in the art.

li" ure 8 indicates diagrrannnatically the wiring` plan for connecting the various parts of thv paratus for a two-phase power teni. A main switch 39 may be provided to start and stop the motor Q5. From the power supplied for the operation of the motor, a shunt circuit may be used to operate a magrnctic relay si itch Ll() which in turn operates a magnetic switch 41 to connect and disconneet the heatini` elements with a suitable source of current. The shunt circuit for operating" the relay switch li0 may be also controlled by a hand switch L12. In order to protec.; the apparatus from excessive heating,

safety thermostat is inserted in the sunpli.'Y pipe Q1. this thermostat acting` when the oil reachesl a predetermined temperature to open the switch 4.0 and thereby the switch ell., cuttingl off the current from the furnace 18. As a further protective measure. provision is made for automatically ren/leringlr the furnace inoperative upon failure of the liouid circulating means. For example, if an electric furnace is used. it may be controlled bv connections as shown in Figure 8. As therein shown. the shuntl circuit containing the relay switch 4l() is hooled up to the wires carrring one of the phases of the current for d the motor Q5. If this phase fails, the relay switch 40 will open at once:y itsI enertoir/ling current being cut off. lf the other phase fails. the ent load on the first phase circuit will burn ou t the switch 3!) an d thus cause the (mening of the relay switch 110. In any case.y opening of the switch Li0 results at once inthe opening! of the inao'netio switch 4:1 and con nicntly in the cuttingr olf of the current supplied to the furnace 18. The ape' the heat supfnssalse cludes the heating of a plurality of baths of liquid to independent and separately controlled temperatures by the utilization of heated liquid from heating means which heat the liquid at a point outside of the baths. The utilization of heated liquid from a common and separate heater may be accomplished in a number of ways, two of which are shown on the drawings by way of example.

Figure 9 illustrates a method of maintaining a plurality of tanks at any desired independent temperatures. The apparatus shown in this figure and in Figure- 10 is conventionally and diagrammatically indicated. The pump 24 sends oil to the furnace 18 where the oil is heated to a desired temperature above that of the hottest treating tank. From the furnace 18 the hot oil is sent through a distributing pipe 44 from which the oil branches to the separate tanks. Each branch pipe is supplied with an automatic valve 45 which is controlled by a suitable thermostat 46 responsive to temperature conditions within the tank. The mechanism by which the oil supply is controlled through the actuation of the automatic valves 45 is old and well known in the art, and per se forms uo part of this invention. The valves 45 are so operated as to admit hot oil in sufficient quantities to maintain the desired temperature in each individual tank. The oil not required for the tanks is by-passed to a discharge pipe 47 through a loaded relief valve 52 by which suflicient working pressure may be maintained in the supply line 44 and which insures a constant movement of oil through the furnace 18 so as to prevent overheating or carbonization of the oil. The oil entering the tanks passes through eventually and leaves by a discharge connection 50 which communicates with the pipe 47. The latter leads to a suitable sump tank 48 from which the oil passes to the pump Q4 through a pipe 49.

Figure 10 shows aslightly different arrangement of apparatus for accomplishing the same result. In this arrangement, the pump 24 forces oil into the furnace 18 from which it is sent through a supply pipe 44 by suitable branches to the several tanks. In order to regulate the temperature of the tanks, comparatively cool oil is simultaneously supplied from the sump tank 48 as by a pump 51 through a supply pipe 56, this cooler oil being mixed with the hot oil in an automatically regulated mixing valve 55 as it enters cach tank, the valve 55 being controlled by a thermostatic device 46 responsive to temperature conditions at any desired point in the tank. As in the apparatus shown in Figure 9, a relief valve 52 and a return pipe 47 is provided to insure constant movement of the oil through the furnace. If the pump 51 be centrifugal or any other type incapable of building up Iexcessive pressures, there need be no return-pipe'for the cool oil.

lHaving thus described certain embodiments of this invention, it should be evident to those skilled in the art that various changes and modifications might be miade ytherein without departing from its spirit or scope as dened by the appended claims.

We claim 1. Apparatus of the class described, comprising a liquid container having apartition therein extending part way to the top thereof and dividing said container into two compartments, a perforated baille plate extending horizontally across one of said compartments above the bottomthereof and vforming a chamber in the lower lportion of said compartment, means for introducing heated liquid into said chamber whereby liquid rises through said baffle plate and spills over said partition into the other compartment, a discharge pipe connecting with said other compartment, and means for heating liquid prior to its introduction into said chamber.

2. Apparatus of the class described, comprising a liquid container, a partition extending part way up within said container and dividing it into two compartments, means for withdrawing liquid from the lower portion of onel of said compartments and for reintroducing the liquid into the container at the bottom of the other compartment, a perforated plate extending horizontally across said other compartment forming chambers above and below said plate, means for heating the liquid withdrawn from the container prior to its reintroduction thereinto, and means responsive to temperature conditions in said other compartment for regulating said heating means. p

3. Apparatus of the class described, comprising a closed tank having a removable cover, a partition extending part way up from the bottom of the tank and dividing the tank int-o two compartments, a perforated plate extending horizontally across one of said compartments forming a chamber in the lower portion of said compartment, a supply pipe entering said chamber having a perforated end section, a pump, a pipe extending from said other compartment to said pump, a heater including electric heating units, a pipe extending from said pump through said heater and connecting with said supply pipe, and means responsive to temperature conditions in said chamber for controlling the current supply to said heating units.

4. Apparatus for heat-treating steel castings, comprising a tank for hot liquid, a furnace containing a pipe coil and an electric heating unit, a pump, piping connecting said tank, pump and coil for continuous circulation of liquid therethrough, a thermostatic element in said tank near the supply pipe,

means responsive to said element for regulating said electric unit, a second thermostatic element in the pipe between the coil and the tank, and means responsive to said second element 'for cut-ting off tlie current from said electric unit when the liquid in the pipe between the coil and tank exceeds a predetermined temperature.

5. Apparatus for heat-treating metal 0bjects, comprising a tank for het liquid, means outside of said tank for heating liquid, a pump, piping connecting said tank, pump and heating means for continuous circulation of liquid therethrough, a thermostatic element in said tank, means responsive to said ele ment for regulating said heating means, a second thermostatic element in the pipe between the heating means and tlie tank, and means responsive to said second element for 2o rendering the heating means inoperative When the liquid in the pipe containingr said second element exceeds a predetermined teinperature.

In testimony whereof ive have ailixed our se' signatures,

KRISTL l A. JUTHE. ALBERT J. HANSON. 

